| In this paper, a series of Al-Si-Cu-Zn-Sn ordinary (0) and rapidly solidification (R) filler metals was developed for brazing low-over-burned Al alloys. The melting point and fragility of the solder were measured through DSC and the determination of brittle ,ruled out the formula do not meet the requirements. The microstucture was analyzed by the SEM ,XRD,EPMA et. The wetting properties and shear properties were measured and analyzed through the wettability test and shear test. The result shows that :the solidus of the rapid solidification solder than ordinary solder 3℃higher, the liquidus of the rapid solidification solder than ordinary solder below 2℃, the interval of crystallization of the rapid solidification solder narrower than ordinary solder 5℃. The rapid solidification solder have well-distribution of elements and fine crystal grain,ordinary solder have ingredients,uneven-distribution of elements ,the different grain size,dendritic crystal. The wetting angle of the rapid solidification solder is smaller than the ordinary solder,and the spreading area increases. The shear strength of the joint of the rapid solidification solder is less than the joint of the ordinary solder.In this paper,we have developed the right formula of the solder Al-6Si-7Cu-2Sn-2Zn, which have good plasticity, low melting point, good wetting ability, brazed joints with good shear strength. The solder can be producted by the industry,which is an ideal solder of the vacuum brazing of the Aluminum alloys.
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